* [PATCH net] tcp: add sanity tests to TCP_QUEUE_SEQ
@ 2021-03-01 18:29 Eric Dumazet
2021-03-01 23:54 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 2+ messages in thread
From: Eric Dumazet @ 2021-03-01 18:29 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski
Cc: netdev, Eric Dumazet, Eric Dumazet, Pavel Emelyanov, Qingyu Li
From: Eric Dumazet <edumazet@google.com>
Qingyu Li reported a syzkaller bug where the repro
changes RCV SEQ _after_ restoring data in the receive queue.
mprotect(0x4aa000, 12288, PROT_READ) = 0
mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer)
syslog shows:
[ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0
[ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0
This should not be allowed. TCP_QUEUE_SEQ should only be used
when queues are empty.
This patch fixes this case, and the tx path as well.
Fixes: ee9952831cfd ("tcp: Initial repair mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212005
Reported-by: Qingyu Li <ieatmuttonchuan@gmail.com>
---
net/ipv4/tcp.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index dfb6f286c1de92aa505ba3554018ecaa3b94fc40..de7cc8445ac035ff2f7d17b93acabd7342144da8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3469,16 +3469,23 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
break;
case TCP_QUEUE_SEQ:
- if (sk->sk_state != TCP_CLOSE)
+ if (sk->sk_state != TCP_CLOSE) {
err = -EPERM;
- else if (tp->repair_queue == TCP_SEND_QUEUE)
- WRITE_ONCE(tp->write_seq, val);
- else if (tp->repair_queue == TCP_RECV_QUEUE) {
- WRITE_ONCE(tp->rcv_nxt, val);
- WRITE_ONCE(tp->copied_seq, val);
- }
- else
+ } else if (tp->repair_queue == TCP_SEND_QUEUE) {
+ if (!tcp_rtx_queue_empty(sk))
+ err = -EPERM;
+ else
+ WRITE_ONCE(tp->write_seq, val);
+ } else if (tp->repair_queue == TCP_RECV_QUEUE) {
+ if (tp->rcv_nxt != tp->copied_seq) {
+ err = -EPERM;
+ } else {
+ WRITE_ONCE(tp->rcv_nxt, val);
+ WRITE_ONCE(tp->copied_seq, val);
+ }
+ } else {
err = -EINVAL;
+ }
break;
case TCP_REPAIR_OPTIONS:
--
2.30.1.766.gb4fecdf3b7-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net] tcp: add sanity tests to TCP_QUEUE_SEQ
2021-03-01 18:29 [PATCH net] tcp: add sanity tests to TCP_QUEUE_SEQ Eric Dumazet
@ 2021-03-01 23:54 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-03-01 23:54 UTC (permalink / raw)
To: Eric Dumazet; +Cc: davem, kuba, netdev, edumazet, xemul, ieatmuttonchuan
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Mon, 1 Mar 2021 10:29:17 -0800 you wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Qingyu Li reported a syzkaller bug where the repro
> changes RCV SEQ _after_ restoring data in the receive queue.
>
> mprotect(0x4aa000, 12288, PROT_READ) = 0
> mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000
> mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
> mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000
> socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
> setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
> connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0
> setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
> sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
> setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
> setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
> recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer)
>
> [...]
Here is the summary with links:
- [net] tcp: add sanity tests to TCP_QUEUE_SEQ
https://git.kernel.org/netdev/net/c/8811f4a9836e
You are awesome, thank you!
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2021-03-01 23:54 ` patchwork-bot+netdevbpf
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